A lightering operation typically involves two crude oil tankers which are manoeuvring in close proximity and operating alongside for transfer of cargo. This is a challenging task for the officer in charge of the decision-making process during the operation, which is based on visual observations and radar measurements. Well trained and experienced officers are necessary to minimize the risk of miscommunication between the ships. Mooring Masters were given a questionnaire focusing on the decision-making process and aspects of the ongoing development of an additional navigation support and guidance system for ship-to-ship operations. The paper discusses the potential for improving the process of decision-making and the operational safety.